The present invention relates to the design and construction of adjustable damping systems for suspension systems. More particularly, the present invention relates to a damping system having separately adjustable damping circuits, one for compression damping and one for rebound damping.
Suspension systems have been used for various applications, such as cushioning impacts, vibrations, or other disturbances experienced by vehicles and machinery. A common application of a suspension system is in bicycles and motorcycles for cushioning impacts or vibrations experienced by the rider when the vehicle is ridden over bumps, ruts, rocks, pot holes or other obstacles. When applied to bicycles, for example, such suspension systems have been positioned in or proximate to the front and rear forks, seat tube, head tube, and in other locations to insulate the rider from impacts.
Suspension systems typically include a spring system comprising one or more coil springs, elastomer springs, air springs, or other types of springs, either alone or in combination. It is often desirable to control the effect of such spring systems using a damping system. With respect to bicycles, as well as other vehicles, the degree of desired damping depends on a variety of variables, such as the speed of the bicycle, the terrain over which the bicycle is being ridden, the structure of the bicycle, the wheel width, and the weight and particular preferences of the rider. It therefore has been desirable to provide adjustable damping to achieve the widest possible range of damping performance for all classes of bicycles, riders, and terrains. Thus, damping systems have been provided with means for adjusting the damping rates.
The amount of damping required during the compression stroke of a suspension system is often different than the amount of damping required during the rebound or expansion stroke of the system. In addition, the compression and rebound damping requirements may change to differing degrees based upon the variables previously described. It is therefore desirable for the compression and rebound damping rates to be adjustable independently of one another.
Conventional suspension systems typically do not permit damping adjustment at all, or do not permit independent adjustment of the compression and rebound rates. This is particularly true for bicycle suspension systems, with respect to which it is of great importance that the suspensions system weigh as little and be as compact as possible. Accordingly, there is a need for a suspension system, and particularly for a bicycle suspension system, having a damping system that provides separately and independently adjustable compression and rebound damping rates.
The problem of how to provide separately adjustable compression and rebound damping is further exacerbated in suspension systems that use a single piston as the mechanism with which to generate most or all of the necessary damping forces. Thus, there is a particular need for a suspension system having a single piston damping system design that provides separately and independently adjustable compression and rebound damping rates, and particularly for a bicycle suspension system having such a damping system.
In addition, conventional suspension systems typically provide a preload adjustment knob for adjusting the preload of a spring system positioned at one end of the suspension system, and a damping adjustment knob for adjusting the system's damping characteristics positioned at the other end of the suspension system. Thus, it is desirable that a damping adjustment system permitting compression damping adjustment independent of rebound damping adjustment utilize a single adjustment actuator for achieving the compression and rebound adjustment.
Accordingly, one object of the present invention is to provide a suspension system, and particularly a bicycle suspension system, having a damping system that provides separately and independently adjustable compression and rebound damping.
Another object is to provide a suspension system having a single piston damping system design that provides separately and independently adjustable compression and rebound damping rates, and particularly a bicycle suspension system having such a damping system.
Yet another object is to provide a suspension system, and particularly a bicycle suspension system, having a damping system that provides separately and independently adjustable compression and rebound damping and that utilizes a single adjustment actuator for achieving the compression and rebound adjustment.